JPS588798B2 - Call method of button telephone device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device, and more particularly to a communication system of the button telephone device.

Conventional button telephone devices use cables with a large number of core wires to connect the main device and the telephone.

However, in recent years, systems have become larger and more multifunctional, and materials and labor costs have also increased, leading to an increase in system costs.

Therefore, providing a means for reducing the number of cable core wires is an effective means for reducing costs.

Therefore, as a means of reducing the number of cable core wires, it is common to move the switching of communication paths such as office lines from the current telephone set to the main unit, as is generally used in exchanges.

However, this conventional method has the disadvantage that the main device becomes large and expensive.

The present invention eliminates these drawbacks of the prior art and provides a telephone call system for a key telephone device that can realize a low-cost device that greatly reduces the number of cable cores between the main device and the telephone.

In order to achieve this object, the present invention provides a key telephone device in which a plurality of key telephones are selectively connected to a plurality of office lines using a main device, a plurality of call lines, and a plurality of control lines. The main device includes clock pulses, a plurality of rows of modulation/demodulation time slot pulses corresponding to the central office line, and a plurality of rows of control signal transmission time slot pulses corresponding to the central office line having a repetition period longer than a repetition period of the modulation/demodulation time slot pulses. a first pulse generator 1, 2, 3, 4.5 for generating a pulse, connected to each of the plurality of office lines so as to correspond to each other, and controlled by a corresponding pulse train of the plurality of trains of modulation/demodulation time slot pulses; a plurality of first time-division switches 21, 22 connected to the communication line so as to correspond to the plurality of button telephones, respectively, and controlled by corresponding pulse trains of the plurality of trains of modulation/demodulation time slot pulses; a plurality of second time division switches 16, 20 compatible with button telephones; a plurality of circulating memories 12, 13, 14, compatible with button telephones whose output sides are connected to the plurality of second time division switches; and the control line. a plurality of writing means 7 for writing control outputs transmitted from the corresponding button telephones via the plurality of control signal transmission time slot pulses into corresponding ones of the plurality of circulating memories in synchronization with the plurality of rows of control signal transmission time slot pulses; ,8,9,10,1
1 and 40, and each of the telephone sets includes a second pulse generator 26 for generating a synchronous time slot pulse substantially synchronized with a corresponding one of the plurality of rows of control signal transmission time slot pulses. , 27, 28, and an operating means 33, 34 including a plurality of office line telephone keys corresponding to office lines, and an AND output between the output of the operating means and the synchronized time slot pulse to obtain the control output from the corresponding button telephone. control output means 31, 32, and 36 for outputting one of the central office lines specified by the control output sent by a designation operation of the central office line telephone key in any one of the key telephones. This is a call system for a button telephone device, characterized in that it is configured to be connected to a button telephone in a time-division manner so that central line calls can be made.

The present invention will be explained in detail below using the drawings.

FIG. 1 is a block diagram showing the entire key telephone device related to the present invention, and shows C0.1...CO. n is the central line, 100
-1 and 100-n are office line circuits provided corresponding to office lines, each of which is connected to the data highway DH.

200-1...200-m are telephones TEL-1,
...This is a telephone-compatible subscriber circuit connected to TEL-m.

TMU is 100-1...100n, 200-1...200-
This is a common circuit that generates a control signal for controlling m.

NET in TEL is a communication circuit, and CU is a telephone control circuit.

In order to explain the operation of the present invention in detail below, circuit diagrams of the route [100-1→DH-→200-1→TEL] in FIG. 1 are shown in FIGS. 2 and 3.

FIG. 2 is a circuit diagram for telephone communication according to the present invention,
1, 27 are counters, 2, 26 are clock pulse generators, 3, 4, 28 are decoders, 5, 10 are inverters, 8
, 11, 14, 15. 31 is an and gate, ? ,9,1
2.32 is an OR gate, 13 is a shift register, 16.
20, 21, 22 are time division switches, 17, 23 are low-pass filters, 19, 25 are transformers, 29 are telephone communication circuits, 30, 36 are hook switches, 33, 34 are telephone key contacts for selecting central office lines, 35 is 37, 38, and 39 are cables, 40 is a flip-flop circuit, ■ indicates the (+) side of the power supply, and E indicates the (-) side of the power supply.

Further, 100 is an office line circuit, 200 is a subscriber circuit,
A plurality of office line circuits and a plurality of subscriber circuits are connected in parallel through communication buses A and B.

Here, multiple office line circuits connected in parallel are provided, one for each office line, but different time slots for gates of the time division switch are set depending on each office line. .

For example, in Figure 2, this time slot is t1,
Another station line is set to j3, the next one is set to t5, etc.

Here, in order to operate the above circuit, first, counters 1 and 27 are connected to clock pulse generators 2 and 26, respectively.
, and further assume that they are synchronized.

When the user raises the handset and presses the central office line telephone key to make a call to the central office line, contacts 33 and 36 become connected.

As a result, the timing pulse T of the output signal from the decoder 28 driven by the output signal of the counter 27 is routed from [decoder 28 → contact 33 → OR gate 32 - → AND gate 31 → cable 37 → flip-flop 40]. It is applied to the input terminal of flip-flop 40.

As a result of the above, a signal for selecting a central office line has been sent from the telephone to the main device.

The sent signal is received by the main device and shifted to shift register 1.
3 is stored.

Here, the timing for inputting to the shift register 13 will be explained.

The square counter 1 is constituted by a plurality of cascade-connected pinary counters, and is driven by a clock pulse train CP which is the output of a clock pulse generator 2.

The time chart of the outputs C1...C10 of counter 1 is shown in the third
It is shown in Figure (4).

Next, the decoder 3 and the decoder 4 are driven by the output of the counter 1, and respective outputs t1...tn, T1...Tn are obtained.

Here, T1...Tn are signals whose pulse width is the period of the output C10 of the counter 1, as shown in FIG. 3(2).

Moreover, as shown in FIG. 3 (5), t1...tn is a signal whose pulse width is the period of CP, and the pulse width of t1...1 is sufficiently small compared to the pulse width of T1...Tn. be.

Furthermore, signals T'1...T' from the telephone set.

and T1...To have the relationships shown in FIG. 3 (2) and (3), and they are synchronized with a certain delay.

FIG. 3(1) is a diagram showing the timing of data in the case of five office lines, and in the figure, LK1...LK5 indicate signals for the office line telephone keys, respectively.

Further, T indicates a unit time for time slotting T1...Tn.

As is clear from this figure, the transmission signal TQ sent from the telephone to the main device is delayed by a certain period of time with respect to T9.

This delay is for correcting the synchronization difference between the counter 1 and the counter 27 by receiving the signal near the center of the pulse width when the main device receives the signal.

In FIG. 2, the flip-flop 40 has a gate pulse, CIO
It is of the type that outputs at the rising edge of .

Therefore, as mentioned above, when the input signal TQ is applied here, the flip-flop 4 synchronizes with the gate pulse C1o.
0 and is applied to one of the input terminals of the AND gate 11.

The output signal at this time is synchronized with T+o.

Here, CtO is the output of count 1.

Next, the shift register 13 outputs [output terminal of shift register 13 → AND gate 14 → OR gate 12-
→ input terminal of the shift register 13] forms a feedback loop, and the shift register 13 receives the clock pulse CP.
It is configured so that the information input here is circulated and stored at a constant cycle.

Therefore, in order to input the signal to the shift register 13,
A timing pulse is output from the OR gate 9 by a circuit constituted by an AND gate 8 and OR gates 7 and 9, and one of the output signals is applied to an AND gate 14 through an inverter 10 to close it.

The other signal is applied to the AND gate 11 to open it, thereby inputting the signal applied from the flip-flop 40 to the shift register 13 through the OR gate 12.

Here, this input timing is t1 and t2 as described above.
Therefore, the storage location in the shift register 13 is also fixed, and the signals are output at timings t1 and t22 one cycle later.

Here, in order to synchronize the input and output of the shift register 13, the storage capacity of the shift register 113 is set to be equal to the steps t1...tn of one cycle of the decoder 3.

As described above, the office line signal of T2 inputted from the telephone is converted to the timing of 1, 1, 12, which is further processed by the AND gate 15 by the pulse of the timing of C1,
Only t1 is made available and applied to the gate terminal of time division switch 1 6.20.

Here, C1 is the output of the first stage of counter 1.

As described above, the time division switches 21 and 22 installed in the office line circuit 100 and the time division switches 16 and 20 installed in the subscriber circuit 200 are opened at the same timing, and calls between the office line and the telephone are This is possible with the following route.

That is, the transmission signal from the office line excites the transformer 25,
By its output, [secondary winding 25-2 of transformer 25→
Hybrid 24 → Time division switch 21 → Call bus B →
Time division switch 16 → low-pass filter 17 → hybrid 18 → primary side 19-1 of transformer 19 → earth E]
A communication current flows through the route, excites the transformer 19, and its output is [secondary side (upper) winding 19-2 of the transformer 19→
Cable 38 → Hook switch 30 → Call circuit 29 → Cable 39 → Secondary side (lower) winding of transformer 19 19-3
→Power supply 35], the communication current flows through the route and is received by the telephone.

In addition, the transmission signal from the telephone energizes the transformer 19 through the same route as described above, and its output causes [the primary winding 19-1 of the transformer 19 → the hybrid 18 → the time division switch 20
→Telephone bus A→Time division switch 22→Filter 23→Hybrid 24→Secondary winding 25-2 of transformer 25→Earth E] A communication current flows through the route, exciting the transformer 25, and the signal is transmitted to the primary of the transformer 25. It is induced in the winding and sent out to the central office line.

Here, the signals on call buses A and B are PAM modulated.

Also, although only one central office line circuit, one subscriber circuit, and one telephone set are shown in Figure 2, in reality, they are connected through communication bus A and B terminals, which are part of the data highway DH, as shown in Figure 1. are connected in parallel.

That is, assume that five circuits are connected in parallel to call buses A and B.

At this time, the external pulse to the gate of the time division switch is t1
(In the case of the circuit 100), t3, t5, t7, and t9 are set.

In this case, the OR gate 7 and the AND gate 8 are provided for each office line, and the input signals t1 and t2 of the OR gate 7 are
and signals corresponding to the input signal TIO of the AND gate 8 are respectively t1, t2; t3 3t4: t53t6s Lr corresponding to the station line circuit gate pulses t1...t9.
t tB; tg t 11o and TI0, T11,
T12, T13, and T14 are set, and each of these circuits is connected by an OR gate 9.

In this state, when another office line is selected and a pulse T1o is received from the telephone, a call can be made with the office line circuit to which the gate pulse t1 has been assigned in the same manner as described above.

As described above, it is possible to talk to any office line by selecting the office line key of the telephone.

Further, in FIG. 2, subscriber circuits are also connected in parallel through call buses A and B, but in this case, the operation is similar to that of circuit 200, allowing calls to be made to any office line.

Also, in the above explanation, the time slots of the time division switch are set as t1, t3, t5, etc., and the storage capacity of the shift register 13 is used twice as much as the required number, and is set every other bit. However, this improves crosstalk characteristics during channel switching.

However, in order to save storage capacity, it is possible to stop every other bit and use the entire storage capacity continuously.

Note that the above explanation does not mention the synchronization system between the clock t1 and the clock pulse generator 26, and between the counter 1 and the counter 27, but since these can be used, they will be explained here. omitted.

In addition, although the above embodiment is explained using a shift register, instead of this shift register, a delay line memory or a random access memory can be used as a circular memory that is program-controlled by a processor or the like and operates in the same manner as described above. It is also possible.

Next, station line acquisition in the present invention will be explained with reference to FIG.

The difference between Fig. 2 and Fig. 4 is that Fig. 4 is the circuit 65 of Fig. 2.
Detailed illustration of the circuits in the figure is omitted, and the circuits 51...71 are added.

In FIG. 4, 1, 27 are counters, 2, 26 are clock pulse generators, 3, 4, 128 are decoders, 5, 1
0, 54, 56.68 are inverters, 8, 11, 14
, 15, 31, 52. 53, 57, 58, 59, 70 are AND gates, ? ,9,12,32,55,62.71
is an OR gate, 13 is a shift register, 19.25 is a transformer, 19-2.19-3 is the secondary winding of the transformer 19, 29 is a telephone one-talk circuit. 30.36 is a hook switch, 33 and 34 are contacts of the telephone key for selecting the central office line, 73 is a contact of the telephone key for holding, ■ is the output side of the power supply, E is the (-) side of the power supply, 40
, 51, 60, 61 are flip-flop circuits, 63 is a transistor, 64 is a relay, 64-1 is its contact, 66
is a photocoupler, and 67-1, 67-2 is a dial contact.

In order to acquire the central office line, the input of central office line acquisition information from the telephone to the shift register 13 is the same as in the previous case.

Next, the output of the AND gate 53 obtained as above is passed through the OR gate 55 and the AND gate 58 allows only the output at the timing t1 to pass therethrough, thereby setting the flip-flop 60.

Further, when the input of the inverter 56 is at a low level (that is, there is no signal input) at the timing t1, the flip-flop 60 is reset.

Therefore, the flip-flop 60 continues to be set only as long as the telephone key 33 is kept being pressed, the pulse T'9 is repeatedly sent from the telephone at the cycle of the counter 27, and the output of the shift register 13 is present. It is reset when the signal is cut off.

The setting of flip-flop 60 causes its output terminal to go high, turning on the emitter-collector of transistor 63 through OR gate 62, activating relay 64, and connecting its contact 64-1.

As described above, a DC loop is formed for the station line, and the station line is captured.

Although FIG. 4 shows the case where there is one office line and one telephone, a circuit of 100a is connected in parallel to point A in the figure, and the input signals t1 of AND gates 57 and 58 are connected to t1 and t, respectively.
3, t5, t7, t9, etc., it is possible to selectively capture multiple office lines from the telephone.

If a large number of telephones are used, this can be done by connecting the circuit 200a in parallel to point A in the figure.

Next, the operation of a system for transmitting dial-in palace information from a telephone to a central office line will be explained.

Dial contact information on the telephone is obtained by detecting the next change in loop current using a photo coupler 66 in the main device.

First, on the input side of the photo coupler 66, [(+) side of power supply 35 → secondary winding 19-2 of transformer 19 → hook switch 30 → dial contact (impulse contact) 67-1
→ Dial contact (shunt contact) 67-2 → Input side of photo coupler 66 → Secondary winding 19-3 of transformer 19 →
In the (→ side) loop of the power supply 35, by operating the dial, the contact 67-2 is connected and the contact 67-1 is disconnected, so that the DC current is interrupted and the current changes,
Dial information is output to the output side of the photo coupler 66, and the output signal controls the AND gate 53 through an inverter 68.

As a result, the AND gate 53 outputs the AND of the output signal from the shift register 13 and the photocoupler 66, and in the same manner as described above, the AND gate 53 outputs the OR gate 55 and the AND gate 66. 57,5
8. Set or reset flip-flop 60 through the circuit of inverter 56.

Here, the cycle of the decoder 3 is set to be sufficiently small compared to the intermittent cycle of the contact 67-1.

This is so that even if the contact 67-1 is disconnected immediately after timing t2 and the invert output 68 becomes low level, the flip-flop 60 continues to be set until t2 comes after the next cycle. .

Therefore, an error corresponding to one cycle of the maximum decoder 3 will occur.

The above conditions are necessary to reduce this error,
This can be made sufficiently small because it is determined independently of the transmission path between the telephone and the main device.

The operation of capturing the central office line has been described above, and next we will explain the operation of operating the hold telephone key on the telephone in this state to place the central office line on hold.

The hold information from the telephone is sent in the same way as the central office line acquisition information.

When the hold telephone key is pressed in the above-mentioned state of station line acquisition, the contact 73 becomes connected, and the signal T14 from the decoder 28 is passed through the contact 73 and input to the shift register 13 through the same route as described above.

At this time, the time slot of input to the shift register 13 is 11. It is 12.

Next, the output signal of the shift register 13 sets the flip-flop 51 at timing t12.

Here, it is assumed that the flip-flop 51 is of the same type as the flip-flop 40.

Therefore, the flip-flop 51 at timing t1
Outputs high level from 2 to t12 after the next cycle,
The output of the AND gate 52, the output of the AND gate 52, the output of the shift register 13, the station line capture information at the timing of 12, and the timing of the counter 1, is passed through the OR gate 55 and point A (transmission bus) to the AND gate 52.
9 input.

On the other hand, with the arrival of the suspension information, the output of the AND gate 53, which has been output so far, is blocked by the inverter 54.

Therefore, since flip-flop 60 is reset, the reset terminal R of flip-flop 61 becomes low level.

Also, the output terminal Q of the flip-flop 60 becomes high level, and this, the signal from the point A, and the timing t2 cause the AND gate 59 to output, the flip-flop 61 is set, and its output Q is passed through the OR gate 62. , the transistor 63 is turned on, the relay 64 is driven, its contact 64-1 is connected, and the central line is held.

Here, the telephone keys 33, 34 and 73 are locked by pressing the commonly used interlocking telephone key, that is, the office line key, and when the held telephone key is pressed and released, when it is restored, the office line key is also restored. It is a structure.

Therefore, by releasing the held telephone key, the central office line and the held telephone key are restored, the contacts 33 and 73 are disconnected, and the input to the shift register 13 is also disconnected, thereby clearing the data.

Therefore, flip-flop 60 is reset and flip-flop 61 remains set.

Next, when the central office line key is pressed again, the contact 33 becomes connected, and the flip-flop 60 is set in the same manner as in the case of acquiring the central office line, and the output Q resets the flip-flop 61 and holds it. is canceled.

The operations of calling, capturing, and holding a call on the central office line have been explained above, but the above-mentioned central office line acquisition method is not only used for simply acquiring the central office line, but also for transmitting other information, such as information on the short contact 67-2 of the dial. It can be applied as a means to eliminate the influence of the inductance of the primary winding of the transformer 25 when transmitting a dial impulse to the central office line, that is, when transmitting a dial impulse.

An example of the implementation circuit is shown in FIG.

The differences between Figure 5 and Figure 2 are 1.2, 3.4 from Figure 2.
is omitted, inverter 91, AND gates 92, 93
, flip-flop 94, transistor 95, contact 9
A relay 96 having 6-1.96-2 is added, and the insertion position of the contact 67-2 is changed.

Here, when the dial is wound up in FIG. 5, its contact 67-2 becomes a contact, and in the same way as the operation described in FIG. It is output at the same timing, and the route is [AND gate 53 → OR gate 55 → AND gate 92 → flip-flop 94 → base of transistor 95], which adds voltage to the base of transistor 95, turns it on, and relays it. 96 and its contact 96-1
．． 96-2 are brought into contact, thereby shorting the primary winding of the transformer 25.

As a result of the above, it is possible to eliminate the influence of the inductance of the transformer 25 when transmitting dial impulses.

Next, the secret information in the method of the present invention will be explained. FIG. 6 is an example of a circuit for secret information used in the method of the present invention. Comparing FIG. 2 and FIG. 6, FIG. 6 shows the circuit 200 of FIG. Part of the shift register 13.

A circuit 201 is a circuit composed of AND gates 11 and 14, an OR gate 12, an inverter 10, and a flip-flop 40, and a shift register 213, AND gates 211 and 214, an OR gate 212, and an inverter 21.
0, similarly configured as flip-flop 240;
In addition, AND gates 216, 218, and inverter 215
, 254, and a flip-flop 251. The circuit 301 is similar to the circuit 201.

Also, 400 is an or gate. Here, in order for FIG. 6 to operate as a secret call circuit, when the telephone connected to the circuit 201 presses LK1 to enter a call on the office line when the office line is idle, the shift register is activated as explained in FIG. 2. The station line selection information LK1 is input and stored in 213.

In this case, telephone calls using 201 are possible.

Next, in this state, the telephone connected to the circuit 301 tries to enter a call on the central office line and presses the central office telephone key LK1.As explained in FIG. 2, the signal for LK1 is input to the flip-flop 340, and Set and gate 31
1 is applied to one input.

Here, the information stored in the shift register 213 is output at timings t1 and t2 as described above. That is [And Gate 218 → Or Gate 40
0 -> AND gate 316 -> Inverter 315] and is applied to the other input of AND gate 311 in such a way as to block the signal from flip-flop 400.

Here, the inverter 217 and the AND gate 216 prevent the AND gate 211 from being blocked by the output signal from the shift register 213.

Therefore, input to the shift resistor 313 is blocked, so it is not possible to enter a talking state.

Also, in this state, the flip flip 251 and shift register 313 have no output, and the inverters 254 and 354 have no output.
output is at high level.

With the above operation, only the telephone that first captures a single central office line can communicate when the central office line is empty.

Next, in the state described above, only one telephone set can be connected to one central office line.

However, in actual use, there are times when it is desired to connect two or more telephones.

In this method, a method for implementing this will be described below.

In Fig. 6, when the telephone key HK mounted on the telephone is pressed, the contact HK becomes connected, and the signal T'14 is sent to the main device in the same manner as described above, and the signal T'14 is sent to the main device in Fig. 3 f5) and (6). The data is stored in the shift register 13 at the timing shown.

The HK information stored in the shift register 213 is
, t12 and sets the flip-flop 251.

Here, the flip-flop 251 is a D-type flip-flop that is set by the trigger pulse 112.

The output of flip-flop 251 then goes high, which is applied to AND gate 218 through inverter 254 to prevent the output signal of shift register 213 from passing therethrough.

As a result of the above, the output signal of the OR gate disappears, and the LK information can be input to the shift register 313.

The above operation allows two or more telephones to make calls on one central office line.

Although the central office line in the above description has been described as a subscriber line connected to an exchange, the present invention can be applied to an extension line of a private branch exchange also being regarded as the central office line.

As described in detail above, according to the present invention, it is possible to greatly reduce the number of cable cores between the main device of a button telephone device and the telephone, which conventionally used a large number of cable cores, resulting in resource saving and cost savings. The practical effects such as reduction and reliability improvement are significant.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall configuration of the system of the present invention, Fig. 2 is a circuit diagram for explaining the communication system in the system of the present invention, Fig. 3 is a time chart for explaining the operation, and Fig. 4 is a diagram of the system of the present invention. 5 is a circuit diagram showing a partial modification of the circuit in FIG. 4, and FIG. 6 is a circuit diagram for explaining central line acquisition and holding in a button telephone device related to the present invention. FIG. 3 is a circuit diagram for explaining secrets in the device.

Claims (1)

[Claims] 1. In a button telephone device in which a plurality of key telephones are selectively connected to a plurality of central office lines using a main device, a plurality of telephone lines, and a plurality of control lines, the main device is equipped with clock pulse and central office line support. a first pulse for generating a plurality of rows of modulation/demodulation time slot pulses and a plurality of rows of control signal transmission time slot pulses corresponding to the office line having a repetition period longer than a repetition period of the modulation/demodulation time slot pulses; a generator; a plurality of first time division switches connected to correspond to the plurality of office lines and controlled by corresponding pulse trains of the plurality of modulation/demodulation time slot pulses; and a plurality of button telephones; a plurality of second keys corresponding to key telephones each correspondingly connected to said telephone line and controlled by a corresponding pulse train of said plurality of trains of modulation/demodulation time slot pulses;
a plurality of circulating memories corresponding to the button telephones whose output sides are connected to the plurality of second time division switches; and a control output transmitted from the corresponding button telephones via the control line. a plurality of writing means for writing into a corresponding one of the plurality of circulating memories in synchronization with a plurality of rows of control signal transmission time slot pulses, each of the telephones having a plurality of rows of control signal transmission means; a second pulse generator for generating a synchronous time slot pulse that is substantially synchronized with a corresponding one of the transmission tagom slot pulses, an operating means including a plurality of office line telephone keys corresponding to the office line, and the operating means and a control output means for taking out the crawler output from the corresponding button telephone by AND outputting the output of the button and the synchronized time slot pulse, and specifying the office line key in any one of the button telephones. A telephone call system for a button telephone device, characterized in that one of the central office lines designated by the control output sent out by an operation is connected to the button telephone in a time-sharing manner so that a central telephone call can be made.